The present invention relates to a container or package used for shipment and storage of computer disk drives, and more particularly, the present invention relates to an anti-motor fret package for multiple disk drives which protects the computer disk drives from vibration and shock which may occur during shipment and storage.
Computer disk drives are common to personal computers, laptop computers, and other computing devices. As with any product, computer disk drives at some point in time must be shipped from a manufacturer or distributor to another location where the disk drives may be used. As understood by those skilled in the art, computer disk drives are precision electromechanical devices which electronically store data and allow data to be manipulated in accordance with the functioning of computing device in which the disk drives are installed. A computer disk drive includes one or more disks or platters which rotate at high RPMs and are driven by a spindle motor. Because of the advances in the manufacture of disk drives, many disk drives now have thicker platters or disks which weigh more and, thus, have more inertia during rotation. Each computer disk drive also includes at least one read/write component known as the xe2x80x9cheadxe2x80x9d which reads and writes data to and from its corresponding platter. During shipment, a disk drive is shipped with its head in the xe2x80x9clanding zone.xe2x80x9d The xe2x80x9clanding zonexe2x80x9d is an area on a platter where the head is positioned when the disk drive is not in use. In previous disk drive construction, the contact of a head against its corresponding platter in landing zone created enough friction to prevent the platter from any rotational movement during the shipment. However, refinements in the construction of some computer disk drives have also resulted in fewer and/or smaller heads being used. Accordingly, for these newer types of disk drives, there is not enough friction between the smaller heads and the landing zone corresponding with each platter to prevent the platters from rotating due to vibration or shock during shipment. Vibrations experienced by these types of disk drives during shipment can cause the platters to partially rotate in repetitive back and forth motions. These small, partial rotations of the platters cause the lubrication to be displaced or separated from the ball bearings and bearing races within the spindle motors which drive the platters. As grease or lubricant separates from the ball bearings and bearing races, the bearings and races become damaged from lack of proper lubrication. This damage is called xe2x80x9cmotor fret.xe2x80x9d When the disk drive is then installed in a computer, the motor fret is significant enough to result in increased motor noise, typically from three to eight decibels. This increase in noise is a defect which makes the disk drive unsuitable for sale to a consumer.
Most multi-pack boxes which are used for shipment of computer disk drives arrange the disk drives on edge and orient them transversely with respect to the long axis of the box. Unfortunately, pronounced vibrations can occur to a disk drive during shipment in such containers. Transverse or side-to-side vibration during shipment results in motor fret.
In accordance with this invention, an anti-motor fret package or container is provided which prevents motor fret. Although the present invention involves a combination of elements, there is also utility with respect to various subcombinations to include a top cover and stabilizing member used in the package. Also in accordance with the invention, methods are provided which facilitate shipment of computer disk drives in a way to avoid motor fret.
In its simplest form, the package or container of the invention includes three major components, namely, a main insert, a top cover, and a cardboard shell. The main insert is constructed of expanded polypropylene material molded to include a plurality of compartments to receive disk drives loaded therein. The compartments are arranged in one or more rows extending longitudinally along the length of the package. The top cover is placed over the main insert and contacts the upper surfaces of the disk drives. A stabilizing member in the form of a central rib communicates with the top cover, and extends longitudinally along the row(s) of disk drives to particularly constrain the disk drives from lateral or transverse movement within their respective compartments. In some embodiments, the central rib is attached to the lower surface of the top cover while other embodiments separate the central rib from the top cover. The main insert, top cover, and central rib are housed within the cardboard shell which is in the form of a corrugated cardboard box.
Typically, the main insert includes two parallel rows of compartments for holding a plurality of disk drives. A longitudinally extending gap separates the rows of disk drives. The central rib is positioned so that it extends along and fills this gap, and makes contact with the disk drives pushing or displacing them transversely against outer edges or walls of their respective compartments. The central rib particularly constrains the disk drives from lateral or transverse motion within their respective compartments, thus minimizing motor fret induced by undesirable transverse or lateral vibration.
Disk drives that are prepared for shipment are often placed in a flexible plastic bag or container for various reasons, including preventing a static charge from damaging the drives. Thus, the disk drives do not have a completely uniform and rigid shape during shipment because of the plastic bag or containers. The main insert compartments could be sized for a tight friction fit with the loaded disk drives; however, this might rip or tear the containers. Furthermore, it is undesirable to have the disk drives firmly wedged within the main insert compartments because it makes the disks drives difficult to load and remove, and damage can occur to the disk drives merely by loading or removing them. The central rib constrains the disk drives within their respective compartments and prevents any movement or displacement of the disk drives; however, the central rib is easily removed which allows the disk drives to be loaded and removed without damage and without undue physical effort.
The central rib in a first preferred embodiment is simply a substantially rectangular shaped extension protruding from the lower surface of the top cover. Other preferred embodiments are disclosed herein which provide different shapes of the central rib. Yet other embodiments are disclosed wherein the central rib is a separate piece which is not permanently attached to the top cover.
Like the main insert, the top cover and central rib may be made of expanded polypropylene or other well known molded packing materials. Additionally, it is contemplated within this invention that the central rib can be made of any type of suitable material which has the strength and resiliency to displace and hold the computer disk drives in their contact positions against the outer walls of their respective compartments. For example, the central ribs could be constructed of plastic, wood, or cardboard, or the central rib could be made of a sufficiently rigid inflatable member.
There are numerous advantages to the invention. First, motor fret can be substantially reduced, if not eliminated. No or minimal changes are required of either the main insert or the cardboard shell. In fact, the only required structural modification to the overall package is the inclusion of the central rib. The disk drives are easily inserted and removed from their respective compartments because the size of the compartments do not have to be modified. In addition to protection from vibration, the disk drives are still protected from normal shock which may occur during shipment (for example, inadvertent dropping or slamming of the package against another object). More importantly, the construction of the newer types of disk drives do not have to be modified to reduce motor fret. These and other advantages will become apparent from the description which follows, taken in conjunction with the accompanying drawings.